What is the geocentric model?

He Geocentric model , Also called geocentric theory, refers to an ancient theoretical model, which considered the planet Earth as the center of the Universe.

This theory has its origins in primitive times before Christ in Ancient Greece and is influenced by the religious support of that time.

Geocentric theory was formulated by Aristotle, philosopher and scientist of Ancient Greece. His ideas were taken up by a group of philosophers, but it was Claudius Ptolemy who first made the papyrus ideas concerning it.

According to this model, the planets, the stars, the celestial bodies, the Moon and the Sun find themselves revolving around it. While the Earth is still. Thus, from this theory the Earth is considered the center of the solar system.

Geocentric theory is one of the oldest theories developed by man in relation to his place in the universe.

Its premises lasted for more than thousands of years, being the dominant theory until the Renaissance.

With the advance of technology, experimental observation and the new conception of science, this model was finally replaced by the heliocentric theory which states that the Sun is the center of the universe and that the rest of the planets revolve around it .

Historical Route on the Geocentric Model

Aristotle (384-322 BCE) was a considered Greek philosopher and scientist, one of the most outstanding thinkers of ancient Greek philosophy.

He initially put forward the ideas that the planets, the Sun and the Moon were moving in exact circles around the Earth. He considered that it was surrounded by spheres and all visible celestial bodies. And that these were the ones that revolved around the Earth.

In attempting to explain the origin of the movement of the planets, Aristotle referred to a divine force as the cause of the movement of all the spheres; From the outermost to the innermost.

At that time, as they looked up at the sky, astronomers could see from the Earth, which remained motionless, like the Sun and the planets were those that moved regularly. This fact is the one that at that time, made think that the Earth was the center of the Universe.

The geocentric model supported this idea. That Earth was the center of the universe. This perspective corresponded to ancient and medieval science.

For the astronomers of that time it was evident that the rest of the universe moved around the Earth, which they regarded as stable and motionless.

It was the planets, the stars, the Sun and the Moon that could be seen moving around the Earth.

For the geocentric model, created by Greek astronomers, it was the celestial bodies that moved around the Earth, following perfectly circular paths.

But at the same time they discovered that the patterns of this movement were not constant. Looking at them with the background of the other constellations or stars that did not move with each other and remained fixed, these bodies showed retrograde movements at the same time they seemed to stop and move in reverse.

Geocentric theory relied on the idea that it refers to the fact that objects fall to Earth.

Geocentrism coincided then with the dominant view in the Middle Ages, concerning theocentrism. Understood as a doctrine in which God was the center of all reality. By then science was a subfield of theology.

To explain the movement of the planets, Greek astronomers devised models in which the planets moved along circles that were assumed to be about circular orbits around Earth.

As astronomers improved their methods of observation and measurement, the models they used became increasingly complicated. However, geocentric theory persisted over time because it worked.

Geocentric Model VS. Heliocentric Model: The top 5 referents

Claudio Ptolemy's conceptions of geocentric theory have remained in force for more than a thousand years. He was one of the Greek astronomers that had greater influence at the time.

He compiled all the scientific knowledge of his time, equivalent to five hundred years of Greek astronomy, and proposed the geocentric system with theories and astronomical explanations that have dominated scientific thought until the sixteenth century.

From his perspective, the Earth was spherical and stationary, while the stars were placed in fixed positions on its surface.

Its main hypotheses are that the celestial elements, the Sun and the Moon move circularly and evenly. The Earth is the heaviest element in the heavens and all things are brought to them. It defines it as spherical and immobile relative to other elements that revolve around it. And, it places it in the center of the universe.

It was the model proposed by this astronomer that was accepted as true. The Catholic Church adopted it as its own, because it coincided with the idea of ​​divine creation, which placed man at the center of his creation.

Ptolemy was one of the Astronomers who changed the vision of the universe and tried to explain scientifically the mechanics of the stars.

It was Nicholas Copernicus (1473-1543) astronomer of the Renaissance, who suggested a replacement for the geocentric system. For him a heliocentric theory could explain the movement of the celestial bodies more simply than the geocentric vision. According to the Copernican model, Earth orbits the Sun along with all other planets.

It was Copernicus who initiated the beginning of a revolution in the field of astronomy. Breaking with the idea of ​​the geocentric model that conceived the Earth as the center of the Universe.

He proposed that it was the Earth and the other planets that revolved around the Sun. In addition, he conceived the idea of ​​Earth's motion, no longer considering it as a motionless planet.

Copernicus took several years to publish his ideas, to modify the theory and remove the Earth from the center of the Universe was a parallel to relegate the importance of man. For this reason, he was worried about offending the Church.

It took several years for his new conception of the Universe, the Sun and the Earth to be completed and universally accepted. In fact, the Church, which Copernicus feared to offend, took more than 50 years to heed his theory.

However, the heliocentric model proposed by the Sun at the center of the universe has as its predecessor Aristarchus of Samos, another Greek astronomer who in the third century BC proposed a model of planets that revolved around the sun.

But by that time his theory was not successful because he had the counterpart, the geocentric theory which until now had no opponents, on the contrary, was in full swing.

It was Tycho Brahe (1546-1601) a Danish astronomer, who proposed a model that attempted to serve as a compromise between geocentric explanation and Copernican theory.

This scientist was recognized for the work he has done prior to the invention of the telescope.

From a careful observation of a comet, Brahe concluded that the orbit of the comet could not be circular. Nevertheless he did not abandon the notions of the geocentric system.

He proposed a model that preserved the old structure but suggested the idea that all the planets except the Earth revolved around the Sun. And this was the one that moved around the Earth.

Galileo Galilei (1564-1642) Italian astronomer considered the father of astronomy, supported the heliocentric model. He discovered that Venus and Mercury went through phases similar to those of the Moon, making it clear that celestial bodies move around other centers than Earth.

He dedicated himself to improving the design of the telescopes and thanks to that he was able to see the moons of the planet Jupiter.

This, coupled with a previously proposed model where Mercury, Venus, Mars, Jupiter and Saturn orbited around the Sun, while the Sun and Moon orbited the Earth, disrupted the geocentric model.

A strong proof of his theory was his publication towards the end of 1610 where he explained that Venus and the Moon had different phases in time, which was easy to interpret with the heliocentric theory but very complex to do it from the geocentric.

At the time of his publications, Galileo showed no concern for the Church as did Copernicus, so he had no qualms in publishing his findings. For this reason, the Church forced him to renounce his theories and imposed a house arrest for life, as a punishment.

Johannes Kepler (1571-1630) mathematician and German astronomer, used Brahe's measurements to determine the exact paths of the planets. This astronomer was able to demonstrate that the planets did not move along circular paths, but that each planet followed an elliptical course, with the Sun in a focus of the ellipse.

This astronomer published the first two laws corresponding to the movement of the planets. These laws make reference to that the planets revolve around Sun, in elliptical orbits and, that the closer to the sun the planet, with greater speed will turn.

Isaac Newton (1642-1727) relied on Kepler's theories and observations from which he established three laws of historical relevance to the functioning of celestial bodies. One of these laws is that of inertia, according to which every body has a tendency to maintain its movement as long as no other external force acts on it.

The other two laws are those concerning dynamics, and action and reaction. Newton was the creator of the universal law of gravitation, demonstrating with it what Kepler proposed about planetary motion.

These laws are valid for celestial objects, leaving no doubt that the operation of solar systems invalidated the geocentric model. Now deceased model that explained how the Sun and Moon surrounded our planet.

Over time, thanks to the records of various civilizations, from ancient Babylonian and Egyptian astronomers, to the Mediterranean contemporaries, a formalized system began to emerge that put Earth at the center of all things.

This idea will last until the eighteenth century, when the inconsistencies corresponding to the model will lead to its abandonment in favor of the heliocentric model.

The geocentric theory was losing strength and the notion that the Earth was not the center of the Universe was increasingly accepted.

A short time later the evidence appeared that the Sun was not, being considered one more among many stars, during centuries XVIII and XIX.

Entering the twentieth century, discovering that the Earth and its solar system are one of the thousands of galaxies present in the Universe, both theories were forgotten.

But both the geocentric and the heliocentric have been of greater relevance in their respective epochs. And center of interest of important as referents of astronomy.